1. Field of Invention
This invention relates to a structure for a suction pipe for an engine of vehicle, which installs an air-cleaner outlet hose connecting the air cleaner and a throttle body.
2. Background of Related Art
Conventionally, a suction system of an engine installed in a vehicle comprises an air cleaner and a throttle body, wherein air is supplied to each cylinder through an intake manifold, and these are disposed in each given space of an engine room.
In the suction system of the engine shown in FIG. 6, an air-cleaner outlet hose 3 connecting an air cleaner 1 and a throttle body 2 is constituted from a bellows portion 3c provided with connecting cylinder portions 3a and 3b on both ends thereof, to make the connecting work easy. At the connecting cylinder portion (an upper cylinder portion 3a) a mounting hole 3d for a suction air temperature sensor 4 and a harness clamp portion 3e for fixing a harness 5 of the sensor 4 are provided. Further, at the connecting cylinder portion (a lower cylinder portion 3b) of the side of the throttle body 2 a mounting hole 3f for a resonator 6 and a mounting hole 3g for a breather pipe 7 (see FIG. 7) are provided.
Other than this structure, there has been proposed such a suction system, wherein a resonator which is extended along the suction pipe is provided at the upstream of the suction path (JP Laid-open Publication No. Hei 4-12161), or wherein the resonator is disposed at the upstream more than the air cleaner (JP Laid-open Publication No. Sho 61-190159).
When assembling the above parts, the suction air temperature sensor 4 is pressed into the mounting hole 3d of the upper cylinder portion 3a to provide the detecting portion inside the path, and the harness 5 extended from the suction air temperature sensor 4 is mounted on the harness clamp portion 3e of the upper cylinder portion 3a. The breather pipe 7 is disposed by being pressed into the upper mounting hole 3g of the lower cylinder portion 3b.
The resonator 6 is pressed into the mounting hole 3f of the lower cylinder portion 3b, a connecting portion is clamped by the clamp 8e and a distal end side of the resonator 6 is fixed by a welding nut 14 of the bracket 13, which is welded to the intake manifold 12 through a bolt 9, a cushion 10 and a washer 11. Further, the surrounding portion of the air cleaner 1 is rigidly fixed by disposing the bracket 15 at its front and rear.
However, since the mounting work of the resonator 6 in the engine room is carried out by fixing the bolt 9, the cushion 10, the washer 11 and the welding nut 14 fixed on the intake manifold 12, it is complicated and takes a long time to work due to many parts to be used and mounting processes to cause to increase the production cost.
Further, the air-cleaner outlet hose 3 is required to have a structure to endure a negative pressure generated in the hose 3 caused by the air passing resistance in the air cleaner 1. As to this resistance against the negative pressure, the bellows portion 3c is the weakest. In case of reinforcing the bellows portion 3c by thickening its wall, since a performance of absorbing the vibration is lowered, normally, a plurality of annular lib and the like are provided inside the bellows portion 3c. However, in this case, it will cause an increase of not only a weight of a production but also production cost.
Accordingly, it is an object of the present invention to provide a suction pipe structure by improving a mounting workability of the resonator on the air-cleaner outlet hose and increasing the rigidity thereof.